Add VectorIconButton functionality to ImageButton.

apps/ui/views/app_window_frame_view.h

Index: apps/ui/views/app_window_frame_view.h
diff --git a/apps/ui/views/app_window_frame_view.h b/apps/ui/views/app_window_frame_view.h
index f967f3e81260271d280b14cb0b09c37640c5b8b3..bc1f026c01aef098577b2a3d25f1618b10c11ed4 100644
--- a/apps/ui/views/app_window_frame_view.h
+++ b/apps/ui/views/app_window_frame_view.h
@@ -11,7 +11,7 @@
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/path.h"
-#include "ui/views/controls/button/button.h"
+#include "ui/views/controls/button/image_button.h"
 #include "ui/views/window/non_client_view.h"
 
 namespace extensions {
@@ -28,7 +28,6 @@ class Event;
 }
 
 namespace views {
-class ImageButton;
 class Widget;
 }
 
@@ -36,7 +35,7 @@ namespace apps {
 
 // A frameless or non-Ash, non-panel NonClientFrameView for app windows.
 class AppWindowFrameView : public views::NonClientFrameView,
-                           public views::ButtonListener {
+                           public views::ImageButtonDelegate {
  public:
   static const char kViewClassName[];
 
@@ -65,7 +64,7 @@ class AppWindowFrameView : public views::NonClientFrameView,
   };
 
  private:
-  // views::NonClientFrameView implementation.
+  // views::NonClientFrameView:
   gfx::Rect GetBoundsForClientView() const override;
   gfx::Rect GetWindowBoundsForClientBounds(
       const gfx::Rect& client_bounds) const override;
@@ -76,7 +75,7 @@ class AppWindowFrameView : public views::NonClientFrameView,
   void UpdateWindowTitle() override {}
   void SizeConstraintsChanged() override;
 
-  // views::View implementation.
+  // views::View:
   gfx::Size GetPreferredSize() const override;
   void Layout() override;
   const char* GetClassName() const override;
@@ -84,7 +83,7 @@ class AppWindowFrameView : public views::NonClientFrameView,
   gfx::Size GetMinimumSize() const override;
   gfx::Size GetMaximumSize() const override;
 
-  // views::ButtonListener implementation.
+  // views::ImageButtonDelegate:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
   // Some button images we use depend on the color of the frame. This